"Mark" == Mark Crispin <mrc(_at_)cac(_dot_)washington(_dot_)edu> writes:
Mark> Now we hear the claim that completely unnecessary restictions
Mark> in headers are necessary because of news software.
who says those restrictions are unnecessary?
Mail systems do not appear to make any actual use of the message-id
header other than for logging (and internally in some odd systems).
None of SMTP, POP3 or IMAP ever use message-ids as protocol
parameters. News, on the other hand, uses message-ids as protocol
parameters _all the time_, both for readers accessing messages and for
server-to-server transfer.
(and, FWIW, I checked about a hundred thousand message-ids taken from
mail messages here, and only one of those had whitespace in and that
was a Chinese spam which had four spaces in place of the domain-part,
almost certainly due to misconfigured or broken spamming software. So
this clearly isn't a feature that anyone actually _needs_, or probably
even wants.)
Mark> And the IETF/IESG is supposed to respect this?
yes
--
Andrew.